A Study on The Behavior and Motivation of Assets Impairment

2006年新会计准则的发布是我国会计规范的重大改革。作为与国际会计准则存在的实质性差异之一，长期资产减值准备一经确认在以后会计期间不得转回的规定从发布之际就引来诸多关注和争议。新会计准则的这项规定在理论上是否合理，它会对上市公司的行为产生何种影响，以及新会计准则的实施效果如何，这些都是值得关注和极具研究价值的议题。 本文以会计准则变迁期间上市公司资产减值的行为和动机作为研究题目，考察了在此期间上市公司对不同资产类别的计提行为和转回行为的差异以及影响资产减值的主要影响因素。区别于以往的研究，本文在考察资产减值的行为特征时，区分了不同的资产减值项目、不同的资产减值方向，而不是简单地考察计提净额。...The announcement of new accounting standards in 2006 is a great reform of Chinese accounting regulation. Assets impairment standard, as one of standards substantially different from IAS, rules that long-term assets impairment is not allowed to reverse in subsequent accounting periods once it was writen-off, which is very attractive and controversial. Is this rule reasonable in theory? What influen...学位：管理学硕士院系专业：管理学院会计系_会计学学号：1752007115104

Preparation of Hg-doped ZnS and degradation of tixic organic pollutions under visible light irradation

用Hg Cl2与zn(AC O)2和nA2S共沉淀法制备Hg掺杂zn S(HgXzn1-XS),研究在可见光激发下(λ>420 nM)HgXzn1-XS对以罗丹明b(rH b)及2,4-二氯苯酚(2,4-dCP)的光催化降解特性。结果表明,HgXzn1-XS(n(Hg)/n(zn+Hg))为7%(简称C0.07)时,光催化活性最好,在可见光(λ>420 nM)条件下能很好的降解rH b和2,4-dCP,反应30 H后,rH b的矿化率和2,4-dCP的降解率分别为39.5%和54.6%。光催化降解rH b,Hg掺杂zn S光催化剂具有良好的稳定性,Hg不分解,催化剂重复使用5次后光催化活性几乎没有损失。同时采用辣根过氧化物酶催化反应吸光光度法和苯甲酸荧光分析法跟踪分析测定rH b降解过程中H2O2和羟基自由基(·OH)的变化量,表明rH b降解机理涉及·OH历程。Zn S nanoparticles doped with mercury( HgXZn1-XS) was prepared by co-precipitation method by Hg Cl2,Zn(Ac O)2and Na2 S.The photocatalytic degradation characteristics of HgXZn1-XS was evaluated by tracing the degradation of Rhodiame B( Rh B) and 2,4-dichlorophenol(2,4-DCP) under visible light irradation( λ > 420 nm).The results showed that the photocatalytic activity for degradation of HgXZn1-XS was best when the doped dosage was 7%( called C0.07).Catalyst C0.07 could degrade Rh B and 2,4-DCP well under visible light irradation( λ > 420 nm) by the research of photocatalytic reaction.In 30 h the mineralization ratio of Rh B and the degradation of 2,4-DCP was 39.5% and 54.6%,respectively.The catalyst showed good stability according to the Rh B photocatalytic degradation experiments.The catalyst showed with no significant changes in catalytic properties and mercury was not resolved after 5 cycles of photocatalytic degradation experiments.The results of the absorptiometry of horseradish peroxidase-catalyzed reaction and benzoic acid fluorescence analysis measuring the variation of H2O2 and hydroxyl radicals during the degradation process showed that the degradation mechanism include the hydroxyl radical process.国家自然科学基金(21377067;21177072); 国家基础科学人才培养基金项目(J1310024

Inflammation-related signaling pathways of differently-methylated DNA from benign and malignant thyroid tumors in one patient

目的:研究同一患者体内甲状腺良性瘤与癌组织在dnA甲基化方面的差异,从而揭示dnA甲基化在肿瘤发生发展中的重要作用。方法:使用基因甲基化芯片技术对同一患者的并发甲状腺癌、甲状腺良性瘤组织样本的基因组甲基化水平进行检测,对筛选出的差异化显著的基因进行生物信息学分析得到功能基因的信号通路,并针对与甲状腺癌明显相关的信号通路进行分析讨论。结果:甲状腺的良性瘤与癌在dnA甲基化水平上存在显著差异;参与恶性肿瘤相关的信号通路包括T细胞受体的信号通路,JAk-STAT信号通路与细胞因子-细胞因子受体相互作用信号通路等炎症相关信号通路。结论:研究得出炎症的相关生物信息学通路与甲状腺肿瘤的发生发展密切相关,为甲状腺恶性肿瘤的发生发展机制的阐明与潜在药物靶点的选择提供新的思路与方向。Objective To determine the possible differences in DNA methylation of benign and malignant thyroid tumors and its role in tumorgenesis and tumor progression.Methods Infinium human methylation 450 bead chip platform was utilized to screen the whole-genome of benign and malignant thyroid tumor tissues surgically removed from a patient for the determination of their DNA methylation levels.The genes with significant differences in methylation were analyzed for their functional pathways with bioinformatics.Results There were significant differences in DNA methylation between benign and malignant thyroid tumor.The inflammation-related pathways, such as T cell, Jak-STAT and cytokine-cytokine receptor signaling pathways involved in the biological process of tumorgenesis and tumor progression.Conclusions The differences in DNA methylation between benign and malignant reveal a close relationship between inflammation and tumorgenesis and tumor progression and provide a novel method for investigation of thyroid cancer development and target drug discovery.国家自然科学基金(编号:81272445); 厦门市科技局国家对台科技合作项目(编号:350Z20121153

Selective dynamical imaging of interferometric data

Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT’s (u, v)-coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v)-coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A* data sethttp://iopscience.iop.org/2041-8205Physic